JPS5868703A - Optical switch - Google Patents

Abstract

PURPOSE:To connect exit wires to a common exit side optical fiber and to constitute a large scale switch matrix, by disposing plural pieces of basic gratings in a matrix shape, branching the plural inlet side optical fibers in a line direction by the number of rows by optical distributors and connecting the same to the corresponding inlet wires of the basic gratings in the row direction. CONSTITUTION:Mechanical and electronic types are used for basic optical gratings 20a-20d, and optical distributors 22a-22d consist of optical transmission media 30 and half mirrors 32. Broken lines indicate the states wherein optical fibers are connected. Semiconductor laser amplifiers and others are used for optical amplifiers 26. a1-a4 denote inlet side optical fibers, b1-b4 denote outlet side optical fibers and (l) denotes the optical fibers in the switch matrix. A 4X4 switch matrix can be constituted by using 4 pieces of 2X2 basic gratings. A large scale matrix is constituted easily by using the small scale basic optical gratings, and this device contributes to the intensification of switching functions in optical communication.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical switch device, and more particularly to an optical switch matrix that can easily increase the number of outgoing lines.

In a 4F telephone exchange, any one of a large number of incoming lines is connected to any one of a large number of outgoing lines, and while the outgoing line is connected, other people out
Similarly, it is necessary that the blinds can be connected selectively. Such an exchange function can be easily realized using a mechanical type, such as a crossbar switch, or a digital type, such as a highway switch that uses memory. For example, crossbar
In mechanical or electronic switching systems that use switches, it is easy to construct a large-scale switch matrix from a small-scale switch matrix called a basic grid. Figure 1 shows a 4x4 switch matrix using a 2x2 basic lattice 10 (subscripts a, b, etc. are used to distinguish between each other), and the circuit configuration is as shown in the figure. It's as simple as that. In this diagram a1
~a4 is 4 incoming lines, b1 to b4 are 4 outgoing lines, ・The points are wired ORs, and the basic grid connects one of the incoming lines to one of the outgoing lines, and at the same time connects the other incoming line to the other outgoing line. Because I can, a! It is possible to connect any one of ~a4 to any one of b1 to b4 at the same time (excluding double selection, of course).

Of course, a switching function is necessary in optical communication, and in this case, any one of the many incoming optical fibers can be connected to any one of the many outgoing optical fibers, and it is easy to use a small-scale basic lattice. It is hoped that it will be possible to construct a large-scale switch matrix. However, the basic optical grid is 1×1 and 2×
Only small-scale models such as 2 were made (crossbar
(e.g. 8×8), the conventional method requires branching, joining, etc. Therefore, it is not easy to scale up.

To fully explain this point with reference to FIG. 2, it is a 20×2 x 2 light M-line grating, and (a) shows the case where four of these are simply used as in FIG. 1. Since there is no branching or joining, the only way to connect is as shown in the diagram.With this, it is possible to connect all of the incoming lines al to a4 to one of the outgoing lines and to one of the outgoing lines to b4, but some people have connected all the outgoing lines. When there are other people, the connection operation is extremely restricted. For example, if al and bl are connected, connection of al and bl is impossible, and if al is connected to b3, connection of al and b4 is impossible. This is an example of the former (al.

b, is) and fiber t+ 'f< is in use, so a
2'tj', 20b and therefore bl using t+f1 history
It is not possible to connect with pIc, and in the rear example, al r
of optical fiber t2 by a3 [for historical purposes, a2+4++b
This depends on the fact that the path of 4 becomes Kosei~''r.Figure 2(b)
If two basic lattices are added to make six basic lattices 20a to 2Of as shown in the figure, the point indicated by -1- is improved by f. That is, al
r Even if the circuit of b3 is established with the paths 20a, 2Of, 2[]d (or 20a, 20e, 20d), al
The circuit of r b4 can be established with paths 20a, 20e, 20d (or 20a, 2Of, 20d). But al + 20 a + 20 e + 20 dr
By b3, the circuit of Ikl r b3 becomes fC&4.
20 c, 2 Of, 2 D b, bl I) a4. When the circuit of bl is created, al r
bl circuit (there is a problem that it cannot be established because the rt optical fiber t3 or t4 is already used. This is shown in Figure 2 (
This problem can be solved by using all seven basic optical lattices as shown in c).

That is, since there is a dotted route, a2→b1 holds true. Using seven optical elementary gratings in this way allows for the same switching operation as the electrical switch matrix shown in FIG. 1, but it is inevitable that the number of elementary gratings will be large, resulting in large size and high cost.

The present invention attempts to completely improve these points and to enable the construction of a large-scale switch matrix with a simple configuration. A plurality of inputs 41 are arranged and each extends in the row direction.
The 1TL optical fiber is branched into r rows by a gold optical splitter and connected to the corresponding input line of each basic optical grating arranged in the direction of each column, and the output line of each basic optical grating arranged in the direction of each column is connected to the corresponding input line in the direction of each column. The optical fibers are connected to corresponding ones of a plurality of extending common output optical fibers by optical couplers. Examples of Venus are shown in FIGS. 3 to 5.

FIG. 6 shows all seven examples in which a 4×4 switch matrix is constructed using four 2×2 optical basic lattices. a1~a.

Input 111 optical fiber, bI-b4 output optical fiber, 20a to 20dld optical basic grating, t switcher)
Optical fiber in IJ box, optical splitter for 22a to 22d, 2
4a to 24d are optical couplers, and 26 is an optical amplifier.

The basic optical grating may be of either a mechanical type or an electronic type; in the case of a mechanical type, the optical transmission paths are switched by fully driving the rotary reflecting mirrors disposed at each intersection of the matrix. As the optical distributor 22, for example, one of the type shown in FIG. 4(a) is used. 3 o are optical transmission media of the same quality as optical fibers, and 32 is a half mirror. The dotted line indicates the state in which the optical fiber is connected. Now, if an optical signal is input from the direction of the arrow F+ force, half of it is transmitted through the half mirror 32, the other half is reflected, and the signal goes out as shown by the arrow 1'2+F3. Since the optical signal energy is halved by this branching, it is amplified by the amplifier 26.

FIG. 4(b) shows an example of the optical coupler 24. This is a bifurcated optical transmission medium, with arrow F! Both the optical signal input from the force direction and the optical signal input from the arrow F2 direction are
It is transmitted in three directions.

The optical amplifier 26 includes (a) a semiconductor laser amplifier, (b)
) Optical amplifier that fully utilizes nonlinear optical crystals, (c) Optical ICE
There are various amplification modules. (,) uses a semiconductor laser biased near the threshold as an amplifier,
Parameters in (b) include IJT optical amplifiers and optical transistors. In addition, (c) a substrate such as GaAs is integrated with a detector, a laser, an optical waveguide, a transistor amplifier, etc.

Since the wiring connections in FIG. 6 are the same as in FIG. 1, the same exchange function as in FIG. 1 can be achieved. The number of basic optical lattices used can be 4, and 7 as shown in Figure 2 (C).
does not require pieces. This advantage becomes even more noticeable as the scale increases. Please use the 2x2 basic optical lattice for the 5th drawing.
6) In the configurations 1 to 1, it is possible to use 9 quasi-main grids.

The 8×8 switch matrix is constructed using the third +v+ switch matrix as a large basic lattice. It is possible to arrange and connect four pieces (as shown in Figure 3). The following will be explained to you as a monk.

As explained above, according to the present invention, a large-scale switch matrix can be easily constructed using a small-scale optical basic lattice lattice, and this greatly contributes to improving the switching function in optical communications.

[Brief explanation of drawings]

Figure 1 is a block diagram illustrating how to configure a switch matrix using an electrical switch type basic lattice, Figure 2 is an explanatory diagram of a switch matrix constructed using an optical basic lattice, and Figure 6 is a block diagram showing the method of configuring a switch matrix using an electrical switch type basic lattice. FIG. 4 is an explanatory diagram of a specific example of a part thereof, and FIG. 5 is a block diagram showing another practical example of the present invention. In FIG. tl'li, 20 is a basic grating, al to a6 are input optical fibers, and b1 to b6 are output (++: 1 optical fiber, 22 is an optical splitter, and 24 is an optical coupler (4)). Applicant Fujitsu Ltd. Representative Minoru Seyanagi, non-physician
4) J) υ) vs.)

Claims (1)

[Claims] A plurality of basic optical gratings are arranged in a matrix in the row and column directions, and a plurality of input optical fibers extending in the row direction are branched by the number of columns by an optical splitter, and each basic optical grating is arranged in the column direction. The outgoing lines of the basic optical grids arranged in each column direction are connected to the corresponding incoming lines of the plurality of common outgoing light beams extending in the column direction (by optical couplers). Characteristic optical switch device.